Notches or beam pockets in foundation walls
Boxes that will form notches for the ends of floor beams would also be inserted into the foundation formwork prior to pouring the concrete (Figure 39). Treat wood beams abutting concrete below grade with preservative to prevent decay, or leave at least 12 mm (1⁄2 in.) of clearance at the sides and ends of the beam for air circulation.
Source : Canada Mortgage and Housing Corporation (CMHC)